This invention relates generally to toy vehicles operated by a clockworks motor, and more particularly to a vehicle of this type in which the motor spring is charged by a pumping action.
Toy vehicles are known, such as those disclosed in the Cookson U.S. Pat. No. 2,057,557 and in the Lohn U.S. Pat. No. 2,587,052, which are operated by a clockworks-type motor, the motor including a spiral spring whose inner end is connected to a rotary shaft and whose outer end is coupled via transmission gears to the drive wheels of the vehicle. Also provided is a wind-up key which turns the spring shaft to wind the spring so that it stores the required energy, the drive wheels being arrested during winding to prevent an immediate discharge of the stored energy.
The term clockworks motor, as used herein, is not intended to apply to a motor having gears operated by a spring to drive the hands of a clock, but to a similar mechanism whose gears provide a transmission link between the spring and the driven wheels of the vehicle.
One drawback of a vehicle having a clockworks motor with a wind-up key is that very small children may not understand the function of the key or may lack sufficient strength or coordination to turn the key. To overcome this drawback, toy vehicles have been developed which do not require a key. Wind-up is effected, as in the Higashi U.S. Pat. No. 3,798,831 and the Darda U.S. Pat. No. 3,981,089, by means of a friction wheel which rolls on the ground surface and is operatively coupled to the spring shaft.
By pressing the vehicle on the ground and moving it along the surface, the friction wheel turns to wind the spring. When the vehicle is thereafter released, the tensioned spring of the motor then unwinds to propel the vehicle through the transmission gears.
A disadvantage of the typical toy vehicle whose spring motor is charged by turning a friction wheel is that winding only takes place when the vehicle engages and moves over the ground surface in a given direction. This presupposes that a child playing with this toy appreciates the fact that the motor can be charged by moving the vehicle in one direction only. But the reality is that small children may lack this understanding and often try to wind up the motor by moving the vehicle back and forth or in the wrong direction.
Also, with friction wheel-operated spring motors, when the floor on which the vehicle to be played is slippery, one must press fairly hard on the vehicle to be sure the friction wheel is engaged thereby and turns when moving the vehicle across the floor. Some children are incapable of applying the pressure necessary for this purpose.
Another drawback of friction wheel wind-up arrangements is that one cannot wind up the spring adequately, except by moving the vehicle a fair distance. When children are playing a racing game, they cannot, with such vehicles, wind up their spring motors at a common starting point.